Lock



0. A. SHANN April 21, 193%.

LOCK Filed May 14, 1935 2 Sheets-Sheet l INVENTOR QASH N ATTORNEY A rifl2E, 19%. Q SHANN 2,038,201

LOCK

Filed May 14, 1955 2 Sheets-Sheet 2 FIGS INVENTOR QASHANN A T TORNE VPatented Apr. 21, 1936 UNITED STATES PATENT OFFICE TelephoneLaboratories,

Incorporated, New

York, N. Y., a corporation of New York Application May 14, 1935, SerialNo.1 21,350

10 Claims.

This invention relates to locks and particularly to looks of thekey-operated type.

An object of the invention is the prevention of fraudulent operation ofa lock by forcing.

According to a feature of the invention means are included'vvherebymutilation or distortion of parts of the lock due to attempts to forcethe lock result'in a positive association of the bolt and other parts ofthe lock which is effective to prevent retraction of the bolt.

- The invention may be applied, to mention only one specific embodimentby Way of illustration, to doors of the type described in Hoyt et al.United States Patent No. 1,667,804 of May 1, 1928','which areparticularly designed for use on telephone coin collectors. The doordescribed in the Hoyt et 'al. patent is designed to protect the lockassociated therewith. However, un-

scrupulous persons have been able in certain-instances to fraudulentlyoperate looks, even when so protected, by inserting a punch through thekeyhole and hammering it until parts of the lock have been so mutilatedthat the bolt may beretracted without the use of a key.

According to a preferred arrangement of the invention, cavities aremilled in the rear cover of the look so arranged that they will receivethe tongue of the key barrel and the end of 'the bolt, respectively,should the attempts at forcing result in bending or displacing theseparts, the a resulting cooperation of the cavities and the tongue andbolt preventing rotation of the key barrel and retraction of the belt.In addition a stationary partition of the lock is provided with aslot\which normally receives a lug on the bolt when the bolt isretracted. Should the attempts at forcing result in lateral displacementof parts of the lock, shoulders provided on the sides 'of the slot arebrought into the path of the lug on the bolt and prevent retractionthereof.

A complete understanding of the invention and of the various desirablefeatures thereof may be gained from a consideration of the followingdetailed description in connection with the annexed drawings in which:

Fig. 1 is a perspective view of a lock constructed in accordance withthe invention, the cover being omitted to show the interior of the lock;

Fig. 2 is an exploded view of the lock shown in Fig. 1;

Fig. 3 is a reduced front view of a coin collector door of a type towhich the lock may be applied, the outline of the lock being shown bydotted lines;

Fig.4 is 'a view of the interior of the lock, certain of the tumblersbeing omitted to show the association of the bolt lugs and the slots inthe partition plate when the bolt is retracted and the partition plateis in normal position;

Fig. 5 is a View similar to that of Fig. 4 except that the partitionplate is shown in an abnormally distorted position and the bolt isprojected;

Fig.6 is an enlarged sectional end view of another portion oftheinterior mechanism showing particularly the normal position of thekey barrel tongue with respect to the rear wall of the lock case;

Fig. '7 is a front view of the portion of the mechanism shown in Fig. 6;

Fig. 8"is a view similar to that of Fig. 6 except for the fact that thekey barrel tongue is shown in an abnormallydistorted position;

Fig. 9 is an enlarged sectional end view of another portion of theinterior of the lock showing particularly the normal position of the endof the bolt with respect to the rear wall of the lock case;

Fig. 10 is a front view of the portion of the mechanism shown in Fig. 9;and

Fig.11 is a View similar to that of Fig. 9 except for the fact that theend of the bolt is shown in abnormally distorted position.

Referring now to the drawings, a lock is shown which may be, so far asthe bolt, tumblers, key barrel, etc., are concerned, of ordinaryconstruction, for example, of the general type described in UnitedStates Patent 1,793,254 issued to me February 1'7, 1931.

The lock shown in the drawings and in connection with which the featuresof the present invention will be described comprises (Figs. 1 and- 2) acasing including a rear wall 2| and a front wall or cover 22, a bolt 23,a key barrel 24, said key barrel being provided with a cap 25 and atongue 26, key operated tumblers or levers 21, 28, 29, 3|, 32 and 33 anda stationary partition 34. The upper faces of the tumblers project intothe paths oflugs 35, 36 and 31 of bolt 23 and. prevent retraction of thebolt unless the tumblers be rotated to move the faces out of the pathsof lugs 35 and 36'and to properly align the slots, which are provided inthe faces to register with lug 31. This movement of the tumblers may bebrought about in the usual manner by the use of a properly designed key.A shoulder 38 is provided on bolt 23, tongue 26 of the key barrelengaging this shoulder and causing retraction of the bolt when the keybarrel is rotated. Cavities 39 and 40 are milled in rear wall 2| of thecasing of the lock, the particular arrangement and application of whichwill be described later.

Stationary partition 34 is adapted to occupy a position in the assembledlock between tumblers 21, 28 and 29 and tumblers 3|, 32 and 33 beingmidway between lugs 35 and 36 of the bolt. The partition is mounted onpins 42, 43 and 44, hole 45 provided in the partition being of a size toprovide a tight fit on associated pin 43 while holes 46 and 4'! areelongated to provide a laterallyslidable fit on associated pins 42 and44. The partition is provided with slots 48 and 49 into which respectivelugs 31 and 52 are adapted. to

slide when the bolt is retracted (Fig. 4). A notch 53 is provided on theupper side of the partition and shoulders 54 and 55 are provided in theside walls of slot 49, the particular purposes of which will bedescribed later.

Referring now for a moment to Fig. 3, a front view (reduced size) of acoin collector housing door of the general type described in Hoyt et a1.United States Patent 1,667,804 is shown, the lock being secured to theinner side of the cover (as shown by the dotted lines) by bolts passingthrough the holes provided in flange extensions 56 and 5'! of rear wall2| of the lock casing. As shown in the drawing the lock is protected bythe door the only access to the lock being through key hole 58.

As pointed out above unscrupulous persons sometimes attempt tofraudulently operate the lock by inserting a punch through key hole 58,placing it in contact with key barrel cap 25 and hammering the punchuntil parts of the lock are sufliciently mutilated to permit retractionof the bolt. The first result of the hammering is usually the partialdestruction of the key barrel cap whereupon the force is thentransferred to the tumblers, and thence to the bolt. The particular partof the lock that ultimately bears the brunt of the forcing attemptdepends somewhat upon the angle at which the punch is held and the shapeassumed by the key barrel capas the hammering continues. For example,the force may be transferred to the tumblers in a glancing mannerresulting usually in moving the tumblers laterally out of their normalposition or the force may be transferred to the bolt in a directionperpendicular to the plane of movement thereof in which instance thetumblers are usually partially destroyed and either the bolt or thetongue of the key barrel (or both) is distorted or displaced.

Let us assume for purposes of description that an attempt has been madeto force the lock in the above manner and that the force has been soapplied that the tumblers have been moved lat erally out of their normalposition rendering them ineffective in retarding the movement of thebolt. However, this same force has also resulted in forcing stationarypartition 34 laterally from its normal position shown in Fig. 4 to theposition shown in Fig. 5. As pointed out above, holes 46 and 4'! of thepartition are elongated thereby allowing lateral movement of thepartition, pin 43 alone preventing such movement. The attempts atforcing usually result in shearing pin 43 thereby allowing the partitionto move sideways as illustrated, before the tumblers have been renderedineffective.

It will be clear from this figure that the displacement of partition 34is effective to prevent retraction of bolt 23 even though the tumblersare ineffective to prevent such retraction for, as shown, shoulder 54 isnow in position to contact the edge of bolt lug 52. If for any reasonthis contactfailed, retraction of the bolt would still be prevented bycontact of bolt lug 31 and notch 53 which is provided in the upper edgeof the partition.

Under certain conditions the partition 34 might be displaced to the leftinstead of to the right as shown in Fig. 5. In such an instance thedisplacement would be effective to prevent retraction of the bolt in thesame manner as above, shoulder 55 contacting lug 52 in this case insteadof shoulder 54 as before.

Let us assume further now that the force instead of acting as abovedescribed, acts squarely against key barrel 24 in such a way that thebarrel is distorted as shown in Fig. 8. A cavity 39 (Figs. 2 and 7) ismilled in rear wall ,2l of the lock casing, tongue 26 in its normalposition (Fig, 6) being out of actual contact with the walls of thecavity. As clearly shown in Fig. 8,

however, distortion of the key barrel resulting from the forcingattempts has brought tongue 26 into a position where it will engage withthe walls of cavity 39, this engagement being effective to preventrotation of the key barrel. Prevention of rotation of the key barrel, ofcourse, prevents retraction of the bolt, even though the other normalretarding parts have been mutilated, due to the cooperation betweentongue 26 and the shouldered portion of the bolt.

Force acting in the manner just referred to often results in distortionof the lower legs GI and B2 of bolt 23. A cavity 49 (Figs. 2 and 10) ismilled in the rear wall 2| of the lock casing, the normal position ofthe bolt being such (Fig. 9) that legs 6| and 62 are out of contact withthe walls of the cavity. Assuming, however, that the force has bent oneor both of the legs backward it can be seen from Fig. 11 that the edgeof the distorted leg will now engage with the bottom wall of cavity 40thereby preventing retraction of the bolt.

It is believed that it will be apparent from the above description thatthe invention provides adequate protection against the several resultsmost likely to occur from the particular fraudulent practice which isintended to be guarded against. That is, if the attempts result inlateral displacement of the tumblers in either direction, partition 34is effective to hold the bolt projected, if key barrel 24 be displacedor distorted cavity 39 serves to prevent operation of the lock and ifthe bolt itself be distorted, cavity 40 is effective to prevent itsretraction.

It will be apparent also from the above description that the protectingmeans do not interfere with or retard in any way the normal operation ofthe lock. As described above and as shown particularly in Fig. 4 thenormal position of partition 34 with respect to the bolt is such thatthe lugs carried by the bolt slide freely into the slots provided in thepartition as the bolt is retracted. As further described and as shownparticularly in Figs. 6 and 9 the normal position of the key barreltongue and the lower legs of the bolt with respect to cavities 39 and40, respectively, is such that the normal movements of these parts isnot interfered with.

While certain embodiments of the invention have been selected fordetailed description, the invention is not, of course, limited in itsapplication to the embodiments described. These embodiments should betaken as illustrative of the invention rather than restrictive thereof.

What is claimed is:

, l. A look comprising a casing, a bolt, a key barrel normally adaptedto rotate when actuated by a key, a tongue on said key barrel forcooperating with the bolt to cause retraction thereof when the barrel isrotated, and a shoulder on a wall of said casing contacted by saidtongue when said barrel is forced toward said wall for preventingsufiicient rotation of the key barrel to completely retract said bolt.

2. A lock comprising a casing, a key barrel, a bolt normally adapted forprojection and retraction under control of said key barrel, and a shoulder on a wall of said casing contacted by a portion of said bolt whensaid bolt is forced toward said wall for preventing complete retractionof the bolt.

3. A lock comprising a casing, a key barrel normally adapted to rotatewhen actuated by a key, and a tongue on said key barrel, a wall of saidcasing having a cavity for receiving said tongue when said key barrel isforced toward said wall for preventing sufiicient rotation of saidbarrel to completely retract said bolt.

4. A look comprising a casing, a key barrel, a bolt normally adapted forprojection and retraction under control of said key barrel and a cavityin a wall of said casing for receiving a portion of said bolt forpreventing full retraction of the bolt when said bolt is forced awayfrom its normal path toward said wall.

5. A look comprising a casing, a key barrel normally adapted to rotatewhen actuated by a key, a tongue on said key barrel, a bolt normallyadapted for projection and retraction under control of said key barrel,a cavity in a wall of said casing for receiving said tongue when saidkey barrel is forced towards said wall for preventing sufficientrotation of said barrel to completely retract said bolt and a secondcavity in a wall of said casing for receiving a portion of said bolt forpreventing full retraction of the bolt when said bolt is forced awayfrom its normal path toward said wall.

6. A look comprising a barrel having a slot for the reception of a key,a bolt, a projection on the bolt, a normally stationary partition havinga slot therein for reception of said projection when the bolt isretracted and a shoulder on a side of said slot contacting with saidprojection when said partition is forced laterally with respect to theaxis of said barrel out of its normal position for other side of saidslot contacting with said projection when said partition is forced outof its normal position in the direction opposite to said firstdirection.

8. A lock comprising a barrel having a slot for the reception of a key,a bolt, a plurality of key operated levers for controlling theretraction of the bolt, a normally stationary partition positionedbetween certain of said levers, and means, efiective when said partitionis forced laterally with respect to the axis of said barrel out of itsnormal position, for preventing complete retraction of said bolt.

9. A lock comprising a casing, a key barrel, a bolt normally adapted forprojection and retraction under control of said key barrel, and ashoulder on a wall of said casing contacted by a portion of said boltupon partial retraction thereof when said bolt is forced toward saidwall, the relative positions of the shoulder and said portion of thebolt being such when the bolt is fully projected that said shoulder isout of the path followed by said portion of the bolt when said bolt isforced toward said wall.

10. A lock comprising a casing, a key barrel, a bolt normally adaptedfor projection and retraction under control of said key barrel, and acavity in a wall of said casing for receiving a portion of said bolt forpreventing full retraction of the bolt when said bolt is forced awayfrom its normal path toward said wall, the relative positions of thecavity and said portion of said bolt being such when the bolt is in itsprojected position that all of the defining edges of said cavity are outof the path followed by said portion of the bolt when said bolt portionis forced toward said wall.

OSCAR A. SHANN.

